Jack



1 B. HASTY.

JACK.

APPL ICATION FILED ocT. 2. 191a.

Patented Aug. 29, 1922.

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. J. B HASTY.

JACK.

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J. B. HASTY.

JACK.

APPLICATION FILED OCT. 2. I918.

Patented Aug. 29, 1922.

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JACK.

Specification of Letters Patent. Patqgnted Aug. 29 1922.

Application filed October 2-, 1918. Serial No. 256,585.

This invention relates in general to jacks and has for its object broadly the provision of means for preventing forcing the jack beyond a predetermined lifting'action well within the capacity of the jack.

A principal object of the invention is the provision of means in a jack for controlling the action so that it will be impossible to giveto the jack more than a predetermined lifting movement, to the end that effort may not be made by exerting too great strain upon the parts to operate the jack beyond its lifting movement with resultant damage to the working parts. I

The invention contemplates the provision of means for accomplishing this purpose, which will not interfere in any way with the normal and usual manner or method of operating a ack in which my invention may be employed, and without greatlv increasing the cost of the article or material contained in its construction.

The invention contemplates an automatic interruption of the chain oi": power transmitting mechanisms beginning at the handle at the power receiving end and ending at the lifting head when the desired limit of elevw tion is reached, and contemplates the immediate operative restoration of the continuity of the chain when the handle is manipulated to lower the jack.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description when considered in connection with the accompanying drawing illustrating a preferred Fig. 5 is a partial View similar to Fig. 2, showing the arrangement of theparts at the end of the lifting action;

Figs 6 is a section taken of Fig. 5; v i

Fig. '7' is a perspective view of the ratchet Fig; Sis an endelevation of the ratchet wheel; and I Fig, 9isa sin1ilarview of the spring provided to return theparts to normal positionafter each actuation.

The jack shown on the .drawingfor the. purpose of illustrating my invention, con .SlSilS of a casing-11 in which is mounted the vertical lifting screw 12 engaging the threaded lift member 13 hearing a lift head 10. The lifting screw 12 is fixed to bevel gear let having bearing upon the bottom of the casing. A prime actuator,comprising a shaft 15 and a driving bevel gear 16 meshing with the gear 14, is provided and is mounted in a bearingbracket or plate 1'1,

secure-cl by screws 18 to thecasing 11 and covering an opening 19 in'its side-wall; The bearings for the shaft 15- comprises a fixed bearing 2-1 and a sliding bearing 22 movable in a bore 23 provided in a neck or extension 24E of the plate 17, a keyor spline 25 being provided-to prevent rotation ofthe sliding bearing 22 scribed. v r I A manipulating device foractuating "the prime actuator comprises a casting 26 em bracing the shaft 15 and having a lever'or handle receiving socket 527 and a driving pawlreceivlng socket 28. The portion 29 of the shaft 15 within the casting 26 is flat sided, being hexagonal in the present instance, and upon the hexagonal part is mounted a ratchet wheel 31. 'A' ratchet pawl 32 is mounted in the socket QSand 15,1101 mally moved by a spring 33 downinto engagemen't with the ratchet wheel 31. A pin and-slot connection 34; is provided in order that the pawl may be arrangedin either Wittfor a purpose to be later deon the line 66 lifting or lowering position, i. eimay drive the ratchet wheel in either direction.

Thesliding bearing 22 is threadedly engaged with a threaded portion 35 of the shaft15, the threads being so arranged that as the prime actuator is operated to progressively elevate the lifting member 13 the sliding bearing moves to the right (viewing Flg. 1). Finally it engages a collar 36 slidably mounted in alignment with an opening 37 in the wall of the casting 26 adjacent the jack casing. This collar has a bevelled forward face 38 which is adapted to engage under a corner 39 of an operating tooth 4x1 of the pawl to lift and maintain this tooth out of engagement with the teeth 42 of the ratchet wheel 31 when the jack had lifted a predetermined amount. It will be manifest that in thus lifting the pawl out of engagement and so maintaining it further manipulation of the manipulative device of the jack does not result in any further lifting or the application of any lifting force, the strokes of the lever or handle being merely idle.

A spring split washer 4.3 is interposed between the ratchet wheel 31 and the end of the casting 26 and this spring normally pushes the ratchet wheel toward the left (viewing Fig. l) i. e. toward the collar 36. lVhen the collar 36 is pushed over by pres sure of the sliding bearing 2:2 the spring is compressed and the collar moved under the pawl.

In order that the parts may be assembled, the casting is cut away as indicated at 4:5 to permit the ratchet wheel, collar and spring to be inserted in place before the shaft 15 is positioned, positioning of the shaft and securing of the plate 17 in position holding the parts assembled.

The opposite corner 46 of the tooth 41 is cut away so that when the finger piece l? of the pawl is turned to permit lowering of the jack, the ratchet tooth 41 will engage the ratchet wheel regardless of the position of the collar 36 and lowering may be accomplished.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In a jack the combination of elevating mechanism, a ratchet manipulating device for operating said elevating mechanism and comprising a ratchet wheel and a tooth movable into engagement therewith, and means having longitudinal movement with respect to the axis of said manipulative device pro-.

portionate to the rotation of said axis for causing engagement beneath the tooth when the elevating mechanism arrives at predetermined position to lift the tooth out of position for engagement with the ratchet.

2. In a jack the combination of elevating mechanism a ratchet manipulating device for operating said mechanism, and means having a screw threaded advance proportionate to the elevation of the elevating mechanism and disengaging the tooth of the ratchet when the elevating mechanism arrives at predetermined position.

3. ln jack, the combination of a rotating prime a .tuator, a manipulating member embracing said prime actuator and having a tooth, a ratchet wheel mounted on said prime actuator, a bevel member embracing said prime actuator, means operable by and movable upon said prime actuator for thrusting said bevel member under the tooth of the ratchet for disconnecting said ratchet when the prime actuator has elevated the jack a predetermined amount.

l. In a jack, the combination of a rotating prime actuator, a manipulating member embracing said prime actuator and having a tooth, a ratchet wheel mounted on said prime actuator, a bevel member embracing said prime actuator, means operable by and movable upon said prime actuator for thrusting said bevel member under the tooth of the ratchet for disconnecting said ratchet when the prime actuator has elevated the jack a predetermined amount, said tooth being bevelled and reversible to permit lowering of the jack without engaging said bevelled member.

5. In a jack the combination of elevating mechanism, a ratchet manipulating device for operating the elevating mechanism and having tooth for actuating said elevating mechanism to raiseand lower a load, and means having longitudinal movement with respect to the axis of said manipulative device proportionate to the rotation of said axis for causing disengagement of the tooth when said elevating mechanism has lifted a load a predetermined distance, said tooth being movable in said disengaged position to a position for engagement with the ratchet to move it in the reverse direction.

6. In a jack the combination of elevating mechanism, a ratchet manipulating device for operating the el vating mechanism and having a tooth movable toward and from a ratchet wheel for actuating said elevating mechanism and means for lifting the tooth away from said ratchet wheel when the elevating mechanism has lifted a load a predetermined distance, said tooth being 1novable from its disengaged position into engagement with the ratchet wheel to move the ratchet wheel 1n a reverse direction.

JOHN B. HASTY. 

